Determining state of charge for battery powered devices including battery powered surface treatment apparatuses

Abstract

A surface treatment apparatus may include a power source having one or more batteries and an apparatus controller configured to estimate a state of charge of the one or more batteries based, at least in part, on an operational mode of the surface treatment apparatus.

What is claimed is: 
     
       1. A surface treatment apparatus comprising:
 a surface cleaning head having an agitator and an agitator motor configured to cause the agitator to rotate; 
 an upright section movably coupled to the surface cleaning head; 
 a cleaning assembly including a dust cup and a suction motor; 
 a power source electrically coupled to the suction motor and the agitator motor, the power source having one or more batteries and a battery controller; and 
 an apparatus controller communicatively coupled to the battery controller through a wireless connection, the wireless connection being established via:
 apparatus communication circuitry coupled to the upright section, the apparatus communication circuitry including an apparatus transmitter and an apparatus receiver; and 
 power source communication circuitry coupled to the power source, the power source communication circuitry including a power source transmitter configured to optically couple with the apparatus receiver and a power source receiver configured to optically couple with the apparatus transmitter. 
 
 
     
     
       2. The surface treatment apparatus of  claim 1 , wherein the apparatus transmitter and the power source transmitter are configured to generate an infrared signal. 
     
     
       3. The surface treatment apparatus of  claim 2 , wherein the wireless connection is bidirectional. 
     
     
       4. The surface treatment apparatus of  claim 1 , wherein the battery controller is configured to communicate a state of charge of the one or more batteries to the apparatus controller. 
     
     
       5. The surface treatment apparatus of  claim 4  further comprising a user interface, the user interface having at least one of a light emitting diode or a liquid crystal display, the user interface being configured to display a visual representation corresponding to the state of charge using at least one of the light emitting diode or the liquid crystal display. 
     
     
       6. A surface treatment apparatus comprising:
 a surface cleaning head having an agitator and an agitator motor configured to cause the agitator to rotate; 
 an upright section movably coupled to the surface cleaning head; 
 a cleaning assembly including a dust cup and a suction motor; 
 a power source having one or more batteries, the power source being electrically coupled to the agitator motor and the suction motor; and 
 an apparatus controller configured to estimate a state of charge of the one or more batteries based, at least in part, on a discharge curve or table associated with an operational mode of the surface treatment apparatus, wherein the apparatus controller is configured to:
 measure a voltage at the apparatus controller; 
 add a voltage drop to the voltage to obtain an estimated power source voltage; and 
 compare the estimated power source voltage to the discharge curve or table associated with the operational mode of the surface treatment apparatus to obtain the estimated state of charge of the one or more batteries. 
 
 
     
     
       7. The surface treatment apparatus of  claim 6  further comprising a user interface, the user interface being configured to display a visual representation corresponding to the estimated state of charge. 
     
     
       8. The surface treatment apparatus of  claim 6 , wherein the estimated voltage drop is determined based, at least in part, on the current draw of the agitator motor. 
     
     
       9. A surface treatment apparatus comprising:
 a surface cleaning head having an agitator and an agitator motor configured to cause the agitator to rotate; 
 a cleaning assembly including a suction motor and a dust cup, the suction motor fluidly coupled to the dust cup and the surface cleaning head, the agitator motor and the suction motor selectively operable in a first operational mode or a second operational mode, wherein a rotational speed of at least one of the agitator motor or the suction motor is different between the first and second operational modes; 
 a power source electrically coupled to the suction motor and the agitator motor, the power source having one or more batteries; and 
 an apparatus controller configured to estimate a state of charge of the one or more batteries, wherein the apparatus controller is configured to:
 determine whether the agitator motor and the suction motor are operating according to the first operational mode or the second operational mode; 
 measure a voltage at the apparatus controller; 
 add a voltage drop to the voltage to obtain an estimated power source voltage; 
 when the agitator motor and the suction motor are operating according to the first operational mode, compare the estimated power source voltage to a first discharge curve or table to obtain the estimated state of charge of the one or more batteries; and 
 when the agitator motor and the suction motor are operating according to the second operational mode, compare the estimated power source voltage to a second discharge curve or table to obtain the estimated state of charge of the one or more batteries. 
 
 
     
     
       10. The surface treatment apparatus of  claim 9  further comprising a user interface, the user interface being configured to display a visual representation corresponding to the estimated state of charge. 
     
     
       11. The surface treatment apparatus of  claim 10 , wherein the voltage drop is determined based, at least in part, on the current draw of the agitator motor. 
     
     
       12. The surface treatment apparatus of  claim 9  further comprising a current sensor configured to measure the current draw corresponding to the agitator motor.